The invention relates to an assembly device for assembling two parallel wooden slats without visible screws, comprising an intercalated fixing element engaged in two positioning grooves arranged side by side in the side faces of said slats separated by a first invisible lower gap, and a fixing screw working in conjunction with the fixing element to secure the two slats.
It is known to use an assembly device formed by a spacer in the form of a double wedge bearing on the oblique flanks of the juxtaposed wooden slats. The fixing screw is inserted after the spacer has been fitted, which requires a relatively large clearance between the slats to allow the head of the screw to pass.
Another conventional system consists in nailing or screwing the slats onto the sleepers by means of nails or visible screws passing directly through the slats. Moisture seeping up by capillarity is then liable to cause premature rotting of the wood.
Another blind fixing device makes use of a reversed U-shaped metal clamp fitted astride the sleeper. Screws are inserted obliquely via the bottom, which makes the assembly time longer and prevents any subsequent disassembly of the slats.
The object of the invention is to achieve an assembly device without visible screws, not requiring any pre-drilling of the wooden slats and allowing assembly and disassembly to be performed from the front face of the slats.
The device according to the invention is characterized in that the fixing element comprises a metal slide having:
a base part equipped with an oblong aperture extending longitudinally in the central part for the screw to pass through,
two securing wings oriented in opposite directions from one another and designed to press in the grooves when the screw is tightened,
and a screw head whose external dimension is greater than the visible second gap which is arranged above the grooves between the upper edges of the two wooden slats.
According to a preferred embodiment, the base part of the slide presents a U-shaped section, and a dish at the closed end of the aperture to house the screw head when the screw has been screwed fully tight. The external width of the base part determines said invisible first gap between the bottom edges of the two slats. The thickness of the second gap is smaller than that of the first gap and hides most of the head of the screw, except for the central part where the gripping indentation for a tool to grip is located.
According to one feature of the invention, the fixing element and the screw are made of stainless steel.
According to an alternative embodiment, the fixing element has two convergent opposite securing wings working in conjunction with at least one inclined bearing face of the positioning grooves arranged side by side in the side faces of the slats.
The invention also relates to a process for assembly of wooden slats to make a floor or an outside terrace, characterized by the following successive steps:
partially screwing at least one screw into a bracing sleeper so as to leave the head of the screw protruding out,
then fitting two wooden slats parallel to one another in a direction perpendicular to the sleeper, inserting a fixing part in the form of a slide in the lateral grooves with a longitudinal sliding movement,
and screwing the securing screw fully tight to achieve final securing of the two slats.
Pre-fitting of the screws and sliding of the fixing parts in the grooves of the wooden slats enables the separating gap between the different slats to be reduced to the minimum while allowing assembly and disassembly from the front face.